Experimental study of hygrothermal properties for building materials

In this thesis, the hygrothermal properties of building materials are studied experimentally and numerically. The properties of 10 building materials which are widely used in Canada were determined using either international standard or well-documented and peer-reviewed approaches. The measured products include OSB, plywood, fiberboard and spruce, stucco, gypsum board, two insulation products, one vapor membrane, and construction paper. The properties that were determined include thermal conductivity, sorption/desorption isotherms, vapor permeability, water absorption coefficient, liquid diffusivity, and air permeability. Those data will be used as the input of advanced heat, air, and moisture movement (HAM) models. The moisture storage and release of building materials during the indoor humidity changes were investigated in this thesis. A test facility was developed to characterize this property, which is referred to as moisture buffering value (MBV). MBVs of five products were determined. It is found that fiberboard has the greatest MBV while plywood has the least MBV. Through the curve fitting of measurement data, the relationship of mass change and time elapsed have been represented by mathematical equations. The HAM model, hygIRC 1D, was used to simulate the MBC experiment. The measured material properties from current work were used as the input for the simulation model. For gypsum board, OSB, and fiberboard the overall agreement between the experimental and simulation results is acceptable. However, the simulated weight changes of plywood and stucco are higher than the measured value. These differences could be the resultant of the variation in material properties of these building products. In addition, parametric analysis was performed. It shows that moisture transfer coefficient has the greatest effect in the numerical simulation of moisture transfer within fiberboard; the sorption isotherm also gives significant influence. Whereas, the liquid diffusivity has almost no effect